This invention relates to a method of operating a battery of coke ovens wherein the oven chambers are adapted to communicate through closable ascension pipes with two gas mains that extend along the battery of coke ovens and incorporate sprays to cool the gases therein, the arrangement being such that charging gases from the coke oven chambers are conducted only into the first gas main during the charging of dried and preheated coal and the gases liberated during the remaining portion of the carbonization of coal charges are discharged only into the second gas main.
The gases produced during the charging of coal into coke oven chambers have a very high dust content. Tar separated out of such gases has a very high dust content which reduces the quality of the tar. The charging gases produced when dried and preheated coal is charged into an oven chamber are particularly heavily laden with dust.
It is known in the art to remove the charging gases and possibly also the gases liberated during the early stages of carbonization in an oven chamber through a separate gas main. These charging gases are passed through a wet precipitator before the gases are combined with distillation gases liberated during the remaining part of the carbonization process. When a special gas main is employed to conduct only charging gases, special action must be taken to keep the pressure of the gases in the gas main at a value which will prevent the entry of air into the gas main. When distillation gases are diverted into a charging gas main, in an arrangement of this type throughout an extended period of time, the dust-laden tar separated out of the gases is obtained together with tar which can be considered satisfactory. As a consequence, there is a decrease in the yield of satisfactory tar.